Default Ruler

The default ruler is based on 1 (i.e. the ruler is:  ... 0.25 . 0.5 . 1 . 2 . 4 ...). TerraBuilder can set the ruler for you, or you can set the ruler yourself. If you choose to let TerraBuilder set the ruler, you can accept the default ruler, or let TerraBuilder determine a better ruler, based on the most frequent UPP among the source files.